code: def test_qrom_cost(constants, cost_ref, k_ref):
      r"""Test that _qrom_cost returns the correct values."""
      # pylint: disable=protected-access
      cost, k = qml.resource.DoubleFactorization._qrom_cost(constants)
  
      assert cost == cost_ref
      assert k == k_ref
  
file_path: pennylane/tests/resource/test_second_quantization.py
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 8 for calling a global function with example usage: test_qrom_cost(constants, cost_ref, k_ref) without return types